Examine source code of Cursor Duck

{
  "manifest_version": 2,
  "name": "__MSG_appName__",
  "version": "1.5.0",
  "description": "__MSG_appDesc__",
  "default_locale": "en",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "background": {
    "scripts": [
      "src/models.js",
      "src/background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "storage",
    "activeTab"
  ],
  "web_accessible_resources": [
    "audio/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "src/models.js",
        "src/render.js",
        "src/effects.js",
        "src/engine.js",
        "src/content.js"
      ],
      "run_at": "document_idle",
      "all_frames": true,
      "match_about_blank": false
    }
  ],
  "commands": {
    "toggle-duck": {
      "suggested_key": {
        "default": "Alt+Shift+D"
      },
      "description": "__MSG_cmdToggle__"
    },
    "next-duck": {
      "suggested_key": {
        "default": "Alt+Shift+N"
      },
      "description": "__MSG_cmdNext__"
    }
  },
  "browser_action": {
    "default_popup": "popup/popup.html",
    "default_title": "Cursor Duck",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "cursor-duck@forlihd",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  }
}